The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for grand white stucco Regency and Victorian terraces typical of Kensington and Chelsea.
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for grand white stucco Regency and Victorian terraces typical of Kensington and Chelsea.
Housing stock in Kensington and Chelsea: Grand white stucco Regency and Victorian terraces; red-brick Queen Anne mansions in Kensington; Edwardian mansion blocks; almost no post-war housing stock.
Character: Internationally wealthy residents; extensive listed building coverage; heritage and streetscape prioritised in every decision.
Article 4: Article 4 Directions covering HMOs, office-to-residential, and basement developments — RBKC has some of the strictest basement policies in London.
Basement policy: RBKC's basement policy (post-2015) limits to single-storey under 50% of garden area; double-storey basements effectively prohibited in residential streets.
Measured existing survey, photographic record, Article 4 and conservation check specific to Kensington and Chelsea before we quote.
2–3 design options at concept stage — alternative layouts, glazing, roof forms.
Site location plan, existing and proposed plans, elevations, sections, D&AS where required.
Part L thermal, Part B fire, Part M accessibility, structural strategy.
Steel beam, foundation, lintel design. Chartered engineer sign-off.
Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.
Single planning or regs submission.
Planning + building regs + structural.
Listed, conservation, complex sites.
Direct answers to the questions Kensington and Chelsea homeowners ask every week about house extension drawings.
Start a free quote →Most standard extensions in Kensington and Chelsea fall under Permitted Development — single-storey rear up to 3m (attached) or 4m (detached), side returns up to half the width of the house. However, Kensington and Chelsea has Article 4 Directions that may remove these rights in specific streets, and flats, listed buildings and conservation areas always need full planning. We check PD eligibility before quoting.
Standard permitted development allows single-storey rear extensions up to 3m (attached house) or 4m (detached) in Kensington and Chelsea. Larger extensions up to 6m/8m are allowed under Prior Approval (Class AA). Flats, listed buildings and Article 4 areas in Kensington and Chelsea are excluded from these PD rights.
Our fixed-fee architectural package starts at £1,225 for a Kensington and Chelsea extension (planning + building regs + structural). Typical Kensington and Chelsea build costs are £2,400–£3,500 per square metre including VAT — so a 25m² side return extension is £60,000–£87,500 to construct.
Kensington and Chelsea has a specific basement policy. RBKC's basement policy (post-2015) limits to single-storey under 50% of garden area; double-storey basements effectively prohibited in residential streets.
Most Victorian terraces in Kensington and Chelsea (particularly in Kensington) benefit from both — a side return extension infills the narrow side passage to create a wider kitchen, a rear extension projects back into the garden. A wraparound combines the two. We recommend the best option at the free site visit.
We cover every London borough with the same fixed-fee approach. If your property sits on a boundary, here are the neighbouring options.
We cover every architectural technology service in Kensington and Chelsea with one chartered team.
From £840. A fixed-fee, end-to-end service — measured survey, scaled drawings, Design & Access Statement where required, Planning P...
From £840. A construction-ready drawing package compliant with every Approved Document — Part A structure, Part B fire, Part L ther...
From £1,225. Every loft type across every {location} roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning ...
From £1,575. {location}'s most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards t...
From £995. Turn your unused {location} garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, fu...
From £1,950. Full architectural technology service for basement digs and cellar conversions in {location} — structural underpinning d...
From £350. Chartered structural engineer calculations for every residential intervention in {location} — steel beams, lintels, pad ...
From £450. End-to-end Party Wall Act 1996 service for {location} — Section 1, 3 and 6 notices, schedule of condition surveys, party...
From £1,225. London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your ...
Free quote in 60 seconds. Fixed fee from £1,225. MCIAT chartered.
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